Remote control of device by telephone or other communication devices

ABSTRACT

A communication device, such as a telephone or a personal computer, controls one or more remotely controlled devices solely over a signaling path, without necessarily establishing an audio path, thus eliminating the need for the remotely controlled device, or its controller, to include DTMF detection hardware or software or an RTP stack. The communication device can include authentication information, which the communication device uses to authenticate itself to the remotely controlled device, so a user of the communication device can remotely control the device without necessarily entering additional authentication information, such as a passcode. The remotely controlled device (or a controller that controls the device) can register with an element that detects user interactions, such as keypad button presses, with the communication device. The registration can identify one or more patterns of user input. If the element detects the specified pattern of user input in a user interaction with the communication device, the element notifies the remotely controlled device (or the controller). Optionally, other application servers can also register with the element to be notified if the user enters the same or a different pattern of input in a user interaction with the communication device.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of U.S. patent applicationSer. No. 10/785,501, filed Feb. 24, 2004 now U.S. Pat. No. 7,406,696,titled “System And Method For Providing User Input Information ToMultiple Independent, Concurrent Applications.”

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

(Not applicable)

BACKGROUND OF THE INVENTION

The present invention is related to remote control of devices, and, inparticular, to remote control of devices using telephones or othercommunication devices using a telephony signaling path.

Many communications and information services are enabled by telephoneaccess to computer applications. A common mode for interacting with suchcomputer applications is through a touch-tone telephone. Services oftenconnect multiple applications to the user. For example, it is possiblefor a voice messaging service to be accessed through a pre-paid service.However, this creates a modality problem. For example, the pre-paidplatform might wish to know when the user presses and holds the “#” keyfor a relatively long time (this being referred to as both the “longpound” and the “long octothorpe”), while the voice messaging platformmight wish to know when the user enters digits, such as for menunavigation. The modality problem is that all digits entered by the usertoday get sent to both applications, as the digits are sent and bothapplications listen to the bearer channel. Each application must beprepared to receive and discard notifications of key presses in which ithas no interest, complicating the design of the application as well aswasting the use of processing and communications resources duringoperation.

Numerous applications have been deployed for use in conjunction with thetraditional time-division-multiplexed (TDM)-based telephone network. Inmany cases the applications simply receive the TDM-based “in-band” mediastream, i.e., the voice channel, and the applications are responsiblefor continually decoding the media and monitoring for the presence ofcertain user input of a signaling nature, such as tones indicating thata particular key on the telephone keypad has been pressed. Certainimprovements to the TDM network have been made, such as the AdvancedIntelligent Network (AIN), which have the goal of separating signalingtraffic from media traffic. However, in practice most of the applicationlogic resides in an “intelligent peripheral” that is coupled along themedia path, because of the low-level, device control nature of theassociated protocols. There are too many messages with too short alatency budget for a total separation of application logic from theIntelligent Peripheral. The result is that application developers writetheir applications for deployment on the intelligent peripheral, usuallywith proprietary intelligent peripheral languages. Thus, AIN does notfulfill the promise of separating application logic from mediaprocessing.

The situation is more complex for the packet-switched environments, suchas Voice-over-IP. Existing approaches such as H.248.1 (MEGACO), SessionInitiation Protocol (SIP) and an in-band technique described in RFC 2833are described in turn.

H.248.1 (MEGACO) has a provision for reporting key press digits detectedor generated by an “endpoint”, which in H.248.1 is a media gateway (MG).The MG can be an IP phone, an access gateway, or a trunking gateway. Inthe case of the IP phone, the IP phone can transmit the key pressesdirectly at the protocol level. In the case of a gateway, the gatewaycan detect the key presses using DTMF detectors. Media Gateway ControlProtocol (MGCP) is a proprietary Cisco protocol that operates in muchthe same manner as H.248.1. These protocols employ a master -slaveapproach in which a Media Gateway Controller (MGC) commands the MG(using a device control protocol signaling link) to connect a tonedetector to an incoming circuit and wait for a digit map match. When theMG detects a key press pattern of interest, it notifies the MGC over thesame signaling link, returning the actual digit string detected.

In H.248.1, however, one and only one MGC may control the resources inan MG. Applications that have an interest in user signaling must be apart of the MGC application—there is no provision for independent,third-party applications to receive user signaling information. In MGCP,a first MGC may “pass off” control to a second MGC, but one and only oneMGC may control a resource at any given time. The limitation of one andonly one controller controlling a resource is a direct result of themaster/slave nature of the MGCP and H.248.1 protocols. That is, theprotocol requires the MG to be in an exclusive relationship to an MGC.Although these protocols also allow for “virtual MGs” within a physicalMG, in which case there may be multiple MGCs serving as masters to theset of virtual MGs in a single physical MG, the virtual MGs are simplypartitions of a physical MG. There is no provision for enabling multipleindependent applications to selectively obtain user signalinginformation from a single stream of user input.

It has been proposed that a peer-to-peer protocol such as the SessionInitiation Protocol (SIP) be used to transport key press signaling, suchas via the SIP INFO method. The proposed mechanism closely follows theprotocol of MGCP and H.248.1, including the use of MGCP and H.248.1messages for specifying digit maps and notifications. However, theproposals have envisioned only a single application requestingnotifications, which is a result of there being no mechanism foraddressing endpoints of interest.

Cisco Systems has introduced a method for transporting DTMF digits usingSIP in the SIP signaling path using the SIP NOTIFY method. However, thismethod has a number of disadvantages. First, notifications can only goto a single egress gateway; it is not possible for a third-partyapplication to register for notifications. Second, the egress gatewayreceives notifications of every DTMF digit, whether it has an interestin them or not. Third, there is no provision for selectively passingthrough or clamping the DTMF tones from the media stream. If the ingressgateway passes DTMF, there is the risk of network elements interpretingboth the in -band DTMF and the corresponding DTMF signaling received viathe NOTIFY mechanism, potentially resulting in incorrect operation.

Another proposed method of transporting key press signaling is to usein-band representations for the keys. For example, RFC 2833 describestransporting key presses as named events, rather than as digitalwaveforms representing the key presses. While this approach uses lessbandwidth and processing resources in the media path, it has seriousdrawbacks that limit its usability. First, a point-to-point mediarelationship between the endpoint and the application is generallyassumed, leaving no provision for third-party involvement withcollecting digits. Although in theory RFC 2833 could be used withthird-party applications, rather complicated and unrealistic setup andoperation are required. Additionally, because of the particular way thatRFC 2833 handles redundancy, it does not meet the reliabilityrequirements for signaling traffic. Moreover, RFC 2833 uses morebandwidth than is necessary, by sending multiple copies of the samepacket for normal, lossless operation. Finally, applications receive allkey presses, whether they have an interest in the key presses or not,making for inefficient use of communication and processing resources.

Many prior systems enable users to remotely control devices, such ashousehold appliances, office equipment or equipment at unmannedlocations, via telephone. In such a system, the user presses buttons onthe telephone keypad to send commands to a remotely controlled device.Most such systems require establishing a voice path to carry DTMFsignals between a remote telephone and the device or a separatecontroller that is connected to the device. (For simplicity, the deviceand such a separate controller are collectively referred to in thisBackground as a remotely controlled device.) Such systems require DTMFdetection hardware or software in the remotely controlled device. Inaddition, if a remote control telephone call is routed over avoice-over-IP (VoIP) or similar packet-switched network to the remotelycontrolled device, the device requires a real-time protocol (RTP) stackto receive the DTMF audio signals, even though the device receives noother audio signals. Thus, expensive special purpose equipment isrequired in or near the remotely controlled device.

Additional complications are introduced if local telephones, i.e.,telephones located on the same premises as the remotely controlleddevice, are to be used to control the device. When a device iscontrolled via a telephone call placed to the device from a remotetelephone (i.e., a telephone not located on the same premises as theremotely controlled device), the device typically employs some form ofauthentication, such as requiring entry of a passcode, to ensure thecaller is authorized to remotely control the device. However, from theperspective of the remotely controlled device, local telephones aretreated the same as remote telephones, in that the same authenticationmethod is used for local telephones as for remote telephones. Forexample, if attempts to remotely control the device from a remotetelephone require entry of a passcode, attempts to control the devicefrom a local telephone also require entry of the passcode, even thoughthe local telephone is in a secure location, such as within the samehouse as the remotely controlled device. Such authentication methods forlocal telephones make the user interfaces to such systems cumbersome andunfriendly.

In some systems, a user of a mobile telephone sends a short text message(SMS message) to a vending machine to authorized a purchase, providebilling information (such as the user's mobile telephone number) and/orsend a product selection to the vending machine. In such systems, theuser must compose the SMS message and send the message to the vendingmachine's address. However, no call is placed to the vending machine.

BRIEF SUMMARY OF THE INVENTION

In accordance with the present invention, a system and method forremotely controlling a remotely controlled device via a communicationdevice, such as a telephone, is disclosed. The system and method controlthe remote device solely over a telephony signaling path, withoutnecessarily establishing an audio path between the communication deviceand the remotely controlled device, thus eliminating the need for theremotely controlled device to include DTMF detection hardware orsoftware or an RTP stack.

In some embodiments, the communication device includes authenticationinformation, which the communication device uses to authenticate itselfto the remotely controlled device, so a user of the communication devicecan remotely control the device without necessarily entering additionalauthentication information, such as a passcode. Such a communicationdevice can be used on the same premises as the remotely controlleddevice, thereby simplifying the user interface to the remotelycontrolled device. In addition, the communication device can be use offthe premises. In either case, the communication device acts as anauthentication token for the user, eliminating the need for the user toenter authentication information to remotely control the device.

In some embodiments, the remotely controlled device (or a controllerthat controls the device) registers with an element that detects userinteractions, such as keypad button presses, with the communicationdevice. The registration can identify one or more patterns of userinput. If the element detects the specified pattern of user input in auser interaction with the communication device, the element notifies theremotely controlled device (or the controller). Optionally, otherapplication servers can also register with the element to be notified ifthe user enters the same or a different pattern of input in a userinteraction with the communication device.

In accordance with the present invention, a system and method forproviding user input information to multiple independent, concurrentapplications is also disclosed.

The applications generate respective subscription messages that areprovided to a device receiving input of a predetermined type from auser, such as key presses on a telephone keypad. The subscriptionmessage for each application identifies a respective pattern of the userinput that the application is to be notified of. The device may receivethe input directly, such as in the case of a telephone that receives keypress information directly from the telephone keypad. Alternatively, thedevice may be of a type, such as a media proxy, that resides along amedia path between the user and the application, in which case thedevice obtains the user input from the media stream.

The device monitors the input from the user to identify the occurrenceof the respective patterns identified in the subscription messages. Uponthe occurrence of the pattern in a given subscription message, thedevice notifies the corresponding application via a signaling channellinking the application with the device. In general, the device onlynotifies the particular application that provided the subscriptionmessage, and thus processing and communications resources are conserved.

The subscription messages use regular expressions that can includevarious types of formats to specify the patterns of interest. Forexample, the formats can specify a single digit (either explicitly or inwildcard form), one of a set of digits, a range of digits, and/or arepeating pattern of digits. The subscription messages can also containtags associated with the regular expressions. When a match is detectedand reported to the application by the device, the tag is also returned,enabling the application to easily determine exactly what response tothe input is appropriate without needing to maintain a large amount ofinternal state information.

Other aspects, features, and advantages of the present invention will beapparent from the Detailed Description that follows.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

The invention will be more fully understood by reference to thefollowing Detailed Description of the invention in conjunction with theDrawing, of which:

FIG. 1 is a block diagram of a first system for signaling user key pressinformation to applications in accordance with the present invention;

FIG. 2 is a block diagram of a second system for signaling user keypress information to applications in accordance with the presentinvention;

FIG. 3 is a block diagram of a third system for signaling user key pressinformation to applications in accordance with the present invention;

FIG. 4 is a block diagram of a fourth system for signaling user keypress information to applications in accordance with the presentinvention;

FIG. 5 is a diagram of a key press buffer and associated pointers usedin any of the systems shown in FIGS. 1-4;

FIG. 6 is a diagram of a schema for a Key Press Markup Language (KPML)used in any of the systems shown in FIGS. 1-4; and

FIG. 7 is block diagram of the system for remotely controlling a devicein accordance with the present invention.

DETAILED DESCRIPTION OF THE INVENTION

The contents of U.S. patent application Ser. No. 10/785,501, filed Feb.24, 2004, titled “System And Method For Providing User Input InformationTo Multiple Independent, Concurrent Applications,” are incorporated byreference herein.

In accordance with the present invention, a method and apparatus isdisclosed for providing user input information to a plurality ofindependent, concurrent applications and for remotely controlling adevice via a communication device, such as a telephone.

Providing User Input Information to a Plurality of Applications

FIG. 1 shows a first embodiment in which an application 10 (which is aSIP User Agent (UA)) directly interacts, on a given two-party dialog,with an “end point device” 12. The application 10 is connected to theend point device 12 by both a SIP connection 14 (for signaling) and oneor more Real-Time Protocol (RTP) connections 16 (for media). In thisscenario, the application 10 requests that the end point device 12report via the SIP connection 14 on key press events that might normallyemanate from the end point device's RTP port 18. The illustratedconfiguration can represent, for example, a toll by-pass scenario wherethe end point device 12 is an ingress gateway and the application 10 isan egress gateway.

In the case shown in FIG. 1, the application 10 requests digitnotification on the same dialog established for the call, between SIPports 20 and 22. The use of SIP and RTP in FIG. 1 is for exemplarypurposes only. Other signaling mechanisms such as H.323 can be used, andother bearer mechanisms such as ATM or TDM can be used.

In general, the end point device 12 may receive the input directly, suchas in the case of a telephone that receives key press informationdirectly from the telephone keypad. Alternatively, the device may be ofa type, such as a media proxy, that resides along a media path betweenthe user and the application, in which case the end point device 12obtains the user input from the media stream. An example of such aconfiguration is shown below. In general, the end point device 12includes hardware and software processing resources and interfaces inaccordance with its function in the system. In particular, the end pointdevice 12 includes hardware for monitoring the user input to detectpatterns of interest, as described in more detail below, and one or moreprocessors programmed to implement the signaling functionality describedherein.

FIG. 2 shows a second embodiment that supports a third-party application24 that is interested in user key presses occurring in the context of anestablished two-party SIP dialog between the end point device 12 and thefirst application 10. The third party application 24 addresses theparticular media stream by referencing an established SIP dialogidentifier that refers to the dialog between the SIP ports 20 and 22.

FIG. 3 shows a third embodiment employing a “media proxy” 26 thatmonitors the media stream among a plurality of endpoints. A media proxyis a device that forwards media streams under the control of a signalingcomponent that provides, at a minimum, instruction as to the source anddestination addresses. In addition to the media forwarding function, themedia proxy 26 can also do light media processing, such as tonedetection. An example of a media proxy is the A1-G2 MF from SnowShoreNetworks, Inc.

In FIG. 3, the media proxy 26 has established connections to a firstendpoint User Agent UAa 28 and a second endpoint User Agent UAb 30. Arequesting application 32 uses dialog identifiers to identify the streamto monitor. The default is to monitor the media entering the end pointdevice. For example, if the requesting application 32 uses the dialogrepresented by SIP ports 34 and 36, then the media coming from UAa RTPport 38 is monitored. Likewise, specifying the dialog represented byports 40 and 42 directs the media proxy 26 to monitor the media comingfrom UAb RTP Port 44. The requesting application 32 can monitor thereverse direction or other, related streams. There could also bemultiple streams if there are multiple audio sources, for example.

As shown in FIG. 4, a plurality of applications may be interested inreceiving different notifications of digit map patterns. Applications 46and 48 make requests directly to, and receive reports directly from, anend point device 50. Other applications 52-1, 52-2, . . . 52-n registerwith a controlling, or “aggregation”, server 54, which collapses thevarious requests into as few as one KPML request to the end point device50.

One problem with employing an aggregation server 54 is its potential tobecome a bottleneck, because it must process all of the requests andforward them on to the end point device 50. Another problem is that somepatterns may have complex inter-key-press timing relationships within apattern, but not across independent pattern requests, thus making itdifficult to specify values for the various timers. Finally, theaggregation server 54 must disambiguate and forward responsesappropriately in the face of conflicting or overlapping expressions fromthe different requesting applications 52. Thus, to avoid such problems,it is generally preferred that the individual requesting applications,such as applications 46 and 48 in FIG. 4, make requests directly to anend point device such as end point device 50. Note that this approachstill supports the aggregation model presented by the aggregation server54.

In addition to reducing network traffic, one of the goals of thepresently disclosed technique is to reduce processing requirements atthe requesting applications. For example, assume the first requestingapplication 46 of FIG. 4 is looking for “***”, while the secondrequesting application 48 is looking for “L#”, the octothorpe keypressed for a time. When the end point device 50 detects the “***”pattern, it would be inefficient to send a report to the secondrequesting application 48. Thus, the end point device 50 sends thenotification only to the first requesting application 46.

The system described herein uses a subscription protocol mechanism,whereby a party such as the application server 32 subscribes to the keypress state of a device such as the media proxy 26 or end point device12. The SIP SUBSCRIBE/NOTIFY mechanism, as described in RFC 3265, can beemployed. If media sessions are set up using the SIP INVITE mechanism,as described in RFC 3261, then requesting applications can use the SIPcall identifiers to identify the media leg to be monitored. Inalternative embodiments, session description protocol (SDP) identifierssuch as Internet Protocol address and Port numbers can be used.

The SIP SUBSCRIBE/NOTIFY mechanism provides a means for handlingmultiple, independent requests. Namely, subscriptions on different SIPdialogs are independent. In addition, a subscription on a particulardialog, with a unique event identifier tag (the “id” tag to the “event”entity in the SUBSCRIBE request) is also an independent subscription forthe purposes of key press handling and reporting.

SUBSCRIBE/NOTIFY protocols provide subscription state management.Following the mechanics of RFC 3261, if an end point device 12 receivesa SUBSCRIBE request on an existing subscription, the end point device 12unloads the current subscription and replaces it with the new one.

One goal of the presently disclosed system is to reduce network trafficby consolidating multiple digit presses into one notification message.The system can take advantage of the fact that many telephonyapplications are interested in not only a single key press, but multiplekey presses. For example, collecting a North American Numbering Plantelephone number requires collecting 10 digits, while collecting aPersonal Identification Number (PIN) code may require collecting 4 to 6digits. The system achieves this goal by having the requestingapplication include regular expressions describing the patterns tocollect. The following section describes one embodiment of a regularexpression syntax that can be employed. This syntax is referred to asDRegex, for digit regular expression. It should be noted that “whitespace” is removed before DRegex is parsed, which enables sensibleprinting in XML without affecting the meaning of the DRegex string.

Table 1 describes the use of DRegex. Table 2 gives some examples ofDRegex regular expression formats.

TABLE 1 DRegex Formats Format Matches digit single digit 0-9 and A-D # #key * * key [digit selector] Any digit in selector [{circumflex over( )}digit selector] Any digit NOT in selector [digit-range] Any digit inrange x Any digit 0-9 . Zero or more repetitions of previous pattern |Alternation {m} m repetitions of previous pattern {m,} m or morerepetitions of previous pattern {,n} At most n (including zero)repetitions of previous pattern {m,n} at least m and at most nrepetitions of previous pattern Lc Match the character c if it is“long”; c is a digit, #, or *.

TABLE 2 DRegex Examples Example Description 1 Matches the digit 1 [179]Matches 1, 7, or 9 [{circumflex over ( )}01] Matches 2, 3, 4, 5, 6, 7,8, 9 [2-9] Matches 2, 3, 4, 5, 6, 7, 8, 9 x Matches 0, 1, 2, 3, 4, 5, 6,7, 8, 9 2|3 Matches 2 or 3; same as [23] 00|011 Matches the string 00 or011 0. Zero or more occurrences of 0 [2-9]. Zero or more occurrences of2-9 *6[179#] Matches *61, *67, *69, or *6# 011x{7,15} 011 followed byseven to fifteen digits L* Long star

Referring again to FIG. 4, a first requesting application 46 requeststhat an end point device 50 report detected key presses. The requestingapplication 46 registers for a pattern, such as “***” (three stars insuccession), using the SUBSCRIBE mechanism. When the end point device 50detects the pattern, it sends a NOTIFY message to the requestingapplication 46, noting the detection of the pattern. Example 1 shows arequest, using an embodiment of a protocol language referred to as theKey Press Markup Language (KPML).

<?xml version=“1.0” encoding=“UTF-8”?> <kpmlxmlns=“urn:ietf:params:xml:ns:kpml” xmlns:xsi=“http://www.w3.org/2001/XMLSchema-instance” xsi:schemaLocation=“urn:ietf:params:xml:ns:kpml kpml.xsd” version=“1.0”>   <request>    <pattern>     <regex>***</regex>   </pattern>   </request> </kpml>

EXAMPLE 1 Single Regular Expression Request

The message in Example 1 is a request registering a set of patterns, ofwhich there is only a single regular expression, that of the three stars(“***”).

A requesting application can also register for multiple patterns. Forexample, the requesting application could look for any of a set ofpatterns “***”, “*1”, “*61”, and “*62”, as shown in Example 2.

<?xml version=“1.0” encoding=“UTF-8”?> <kpmlxmlns=“urn:ietf:params:xml:ns:kpml” xmlns:xsi=“http://www.w3.org/2001/XMLSchema-instance” xsi:schemaLocation=“urn:ietf:params:xml:ns:kpml kpml.xsd” version=“1.0”>   <request>    <pattern>     <regex>***</regex>    <regex>*1</regex>     <regex>*61</regex>     <regex>*62</regex>   </pattern>   </request> </kpml>

EXAMPLE 2 Multiple Regular Expressions Request

There are different techniques that can be used to determine whatpattern matches a given key press string, including for example longestmatch, shortest match, or most specific match. The matching algorithm touse can be specified in the KPML message. Although in many cases thelongest match will be preferable, this technique has the problem thatthe system will always wait for the next digit, even if the best matchhas occurred. That is, all key press collection events end with atimeout.

To improve the user experience by having fast reporting of a match,while maintaining the longest match property, the system uses a set ofspecial timers and the specification of an Enter Key Sequence. Thetimers are the critical timer, the inter-digit timer, and the extradigit timer. The critical timer is the time to wait for another digit ifthe collected digits can match a pattern. The extra timer is the time towait after the longest match has occurred (presumably for the returnkey). The inter-digit timer is the time to wait between digits in allother cases. Note there is no start timer, as that concept does notapply in the KPML context.

The Enter Key Sequence is a method whereby one specifies a key press orstring of key presses that indicates to the system that entry iscomplete. The system reports immediately with a match or no match errorupon receipt of the Enter Key Sequence. For convenience, the system doesnot send the Enter Key Sequence in the report. This saves the requestingapplication from having to trim irrelevant information. Note that theEnter Key Sequence cannot also be a substring in the regular expression.

For patterns such as the long octothorpe, applications instruct thedevice what constitutes “long” by setting a “longtimer” attribute in the<pattern> tag to the number of milliseconds desired. Some phones,particularly private branch exchange (PBX) phones, transmit a digit fora preset length of time, such as 50 ms, irrespective of how long theuser presses the respective key. To enable applications to respond tosaid devices, applications may indicate to the device to consider arepetition of a key press within the longtime time period. Applicationsindicate this behavior to the device by setting the longrepeat attributeto “true” in the <pattern> tag.

Example 3 shows an example of a request that registers for a longoctothorpe. With a longtimer value of 2000, the device will look for aminimum key press duration of two seconds (2000 milliseconds). Thisexample also directs the device to match a succession of octothorpe keysfor two seconds as long key press duration by setting longrepeat totrue.

<?xml version=“1.0” encoding=“UTF-8”?> <kpmlxmlns=“urn:ietf:params:xml:ns:kpml” xmlns:xsi=“http://www.w3.org/2001/XMLSchema-instance” xsi:schemaLocation=“urn:ietf:params:xml:ns:kpml kpml.xsd” version=“1.0”>   <request>    <pattern longtimer=“2000”longrepeat=“true”>     <regex>L#</regex>    </pattern>   </request></kpml>

EXAMPLE 3 Long Octothorpe Request

Some applications care to continuously monitor the stream for aparticular pattern, while other applications look for only a singleoccurrence of a particular pattern, at which time the application isfinished monitoring the end point device or may register a different setof patterns. The first type of request is referred to as a “persistent”request, while the second type is termed a “one-shot” request. Thesystem provides for the requesting application to specify the nature(persistent or one-shot) of the request.

It is advantageous to refrain from notifying applications of key pressesthat are not of interest. However, it is possible that a human user maypress spurious keys or accidentally press an incorrect key. Applicationsneed to perform error recovery in this situation. The disclosed systemaddresses this problem by starting an inter-digit timer upon detectionof the first key that matches the first character of any regularexpression in a subscription. This inter-digit timer restarts afterevery key press detected. If the inter-digit timer expires, the endpoint device sends a failure notification to the requestingapplication(s) for which the key presses started to match patterns. Thisnotification enables the requesting application to take differentactions based on the incomplete key presses.

Another situation that can occur is for the end point device to startcollecting key press events and the media dialog to terminate before apattern matches. Again, the end point device sends the key pressescollected up to the point of the dialog termination to the requestingapplication.

The system and protocol described herein could use any of a variety ofmessage transport mechanisms. As described herein, one preferredtransport employs SIP SUBSCRIBE and NOTIFY requests to transport an XMLmarkup called KPML. Those skilled in the art could derive alternaterepresentations for the protocol messages described herein, such asASN.1 notation for example.

As shown in Example 3, a KPML message contains a <request> entity thatincludes a <pattern> tag with a series of <regex> elements. The <regex>element specifies a digit pattern for the device to report on. Because arequesting application may need to know which <regex> of a plurality of<regex>s matched, KPML supports a tag attribute to the <regex> element.When there is a match, the report from the end point device includes thetag of the match's <regex> element. Example 4 shows the case where aseven-digit number matches the “local” tag, a 1+ten-digit number matchesthe “Id” (or long distance) tag, and a 011 followed by a number and fiveto fifteen digits matches the “iddd” (or international direct distancedialing) tag. A sample response is in Example 5.

<?xml version=“1.0” encoding=“UTF-8”?> <kpmlxmlns=“urn:ietf:params:xml:ns:kpml” xmlns:xsi=“http://www.w3.org/2001/XMLSchema-instance” xsi:schemaLocation=“urn:ietf:params:xml:ns:kpml kpml.xsd” version=“1.0”>   <request>    <pattern extradigittimer=“1000”interdigittimer=“5000”>     <regex tag=“local”>x{7}</regex>     <regextag=“ld”>1x{10}</regex>     <regex tag=“iddd”>011x{5,15}</regex>   </pattern>   </request> </kpml>

EXAMPLE 4 Use of a Tag to Identify which Pattern Matched

<?xml version=“1.0” encoding=“UTF-8”?> <kpmlxmlns=“urn:ietf:params:xml:ns:kpml” xmlns:xsi=“http://www.w3.org/2001/XMLSchema-instance” xsi:schemaLocation=“urn:ietf:params:xml:ns:kpml kpml.xsd” version=“1.0”>   <response code=“200” text=“OK” digits=“17035551212”tag=“ld”/> </kpml>

EXAMPLE 5 Tagged Response

A requesting application may advantageously use the tag attribute toencode, for example, state information. In this way, the requestingapplication can be a stateless, stimulus driven application. By usingthe tag attribute to carry state, the requesting application need notcarry per-session state. This results in a significant savings in memoryand processing requirements at the requesting application, thus offeringhigher scale and performance for the application.

For example, Example 6 shows the request for a first device, whileExample 7 shows the request for a second device. The server can tell thedifferent requests apart from the unique prefix, in this case “id00” and“id01” for Example 6 and Example 7, respectively. Note that the tags areopaque strings and can contain however much state information the clientrequires. In the examples here, the identifiers “id00” and “id01” areenough to associate the results with a session. The identifiers can haveany arbitrary state information that is meaningful to the application.For example, a tag might be “from-host-192.168.1.12 at step 24cookie=‘23d0ij32d0ioicq3icoiqwjemf’”, representing host information,sequence information, and arbitrary data.

<?xml version=“1.0” encoding=“UTF-8”?> <kpmlxmlns=“urn:ietf:params:xml:ns:kpml” xmlns:xsi=“http://www.w3.org/2001/XMLSchema-instance” xsi:schemaLocation=“urn:ietf:params:xml:ns:kpml kpml.xsd” version=“1.0”>   <request>    <pattern extradigittimer=“1000”interdigittimer=“5000”>     <regex tag=“id00-local”>x{7}</regex>    <regex tag=“id00-ld”>1x{10}</regex>     <regextag=“id00-iddd”>011x{5,15}</regex>    </pattern>   </request> </kpml>

EXAMPLE 6 Use of a Tag to Identify Server State (Part 1)

<?xml version=“1.0” encoding=“UTF-8”?> <kpmlxmlns=“urn:ietf:params:xml:ns:kpml” xmlns:xsi=“http://www.w3.org/2001/XMLSchema-instance” xsi:schemaLocation=“urn:ietf:params:xml:ns:kpml kpml.xsd” version=“1.0”>   <request>    <pattern extradigittimer=“1000”interdigittimer=“5000”>     <regex tag=“id01-local”>x{7}</regex>    <regex tag=“id01-ld”>1x{10}</regex>     <regextag=“id01-iddd”>011x{5,15}</regex>    </pattern>   </request> </kpml>

EXAMPLE 7 Use of a Tag to Identify Server State (Part 2)

Some devices buffer entered digits, and applications behave differentlywith respect to such buffered digits. Some applications may require thata user enter key presses only as the application is ready to receivethem, in which case any key presses entered prematurely should beignored or discarded. Other applications enable a user to “barge”through prompts or other delays in the user interface by entering keypresses in advance of their prompts, for example, and then acting on thebuffered key presses rather than discarding them.

In the disclosed system, the default is that the matching specified bynew requests is carried out with respect to buffered digits first, suchoperation enabling “barging” behavior by the user. However, the protocolprovides a <flush> tag in the <pattern> element to specify whether thebuffer should be flushed before any matching operations begin, which hasthe effect of ignoring any digits entered before receipt of the KPMLrequest. Additional detail on the digit buffering mechanism is providedbelow in conjunction with a description of key press “quarantining.”

As mentioned above, an end point device may support an inter-digittimeout value, which is the amount of time the end point device waitsfor user input before returning a timeout error result on a partiallymatched pattern. The application can specify the inter-digit timeout asan integer number of milliseconds by using an inter-digit timerattribute to the <pattern> tag. The default is 4000 milliseconds. If theend point device does not support the specification of an inter -digittimeout, the end point device silently ignores the request. If the endpoint device supports the specification of an inter-digit timeout, butnot to the granularity specified by the value presented, the end pointdevice rounds up the requested value to the closest value it cansupport.

KPML messages are independent, a property that enables multiplerequesting applications to simultaneously monitor a stream withoutinteracting with each other. One result of this independence, however,is that it is not possible for a requesting application to know whethera following request from another application will enable barging or wantthe digits flushed. Therefore, the end point device quarantines alldigits detected between the time of a notification and theinterpretation of the next request, if any. If the next requestindicates a buffer flush, then the end point device flushes allcollected digits from consideration from KPML requests received on thatdialog with the given event id. If the next request does not indicatethat buffered digits should be flushed, then the end point deviceapplies the buffered digits (if possible) against the digit mapspresented by the request's <regex> tags. If there is a match, the endpoint device issues the appropriate notification. If there is no match,the end point device flushes all of the collected digits on thatrequest's buffer.

By default, the end point device transmits in-band tones (RFC 2833events or actual tones) on the media channel in parallel with digitreporting via the signaling channel. Note that in the absence of thisbehavior, a user device could easily break called applications. Forexample, consider a personal assistant application that uses “*9” forattention. If the user presses the “*” key, the device holds the digitlooking for the “9”. However, the user may enter another “*” key,possibly because they accessed an IVR system that looks for “*”. In thiscase, the “*” would get held by the device, because it is looking forthe “*9” pattern. The user would probably press the “*” key again,hoping that the called IVR system just did not hear the key press. Atthat point, the user device would send both “*” entries, as “**” doesnot match “*9”. However, that would not have the effect the userintended when they pressed “*”.

On the other hand, there are situations where passing through tonesin-band is not desirable. Such situations include call centers that usein-band tone spills to affect a transfer. For those situations, a digitsuppression tag “pre” can be used in conjunction with the <regex> tag toindicate that the transmission of digits in the media stream should besuppressed. There can only be one <pre> in any given <regex>. An exampleof a request including a suppression tag is shown in Example 8.

If there is only a single <pattern> and a single <regex>, suppressionprocessing is straightforward. The end point device passes digits untilthe stream matches the regular expression <pre>. At that point, the endpoint device will continue collecting digits, but will suppress thegeneration or pass-through of any in-band digits. When reporting on amatch, the end point device will indicate whether it suppressed anydigits by including an attribute “suppressed” with a value of “true” inthe digit report.

<?xml version=“1.0” encoding=“UTF-8”?> <kpmlxmlns=“urn:ietf:params:xml:ns:kpml” xmlns:xsi=“http://www.w3.org/2001/XMLSchema-instance” xsi:schemaLocation=“urn:ietf:params:xml:ns:kpml kpml.xsd” version=“1.0”>   <request>    <pattern>     <enterkey>#</enterkey>    <regex><pre>*8</pre>x{7}|x{10}</regex>     <regex>*6</regex>   </pattern>   </request> </kpml>

EXAMPLE 8 Digit Suppression

In Example 8, the end point device will begin to suppress digits afterreceiving the string ‘*8’. It then looks for seven or ten digits. If itreceives something other than a digit, receives the enter key sequence,or times out, then the end point device will return an error report.Note the second pattern, <regex>*6</regex> does not start the digitsuppression method.

Digit suppression can be optional for a device. If a device is notcapable of digit suppression, it should ignore the digit suppressionattribute and never send a suppressed indication in the digit report. Inthis case, it will match concatenated patterns of pre+value.

At some point during digit suppression, the end point device willcollect enough digits to the point it hits a <pre> pattern. Theinter-digit timer attribute indicates how long to wait once the userenters digits before reporting a time-out error. If the inter-digittimer expires, the endpoint issues a time-out report and transmits thesuppressed digits on the media stream.

Once the end point device detects a match and it sends a NOTIFY requestto report the digit string, the end point device stops digitsuppression. Clearly, if subsequent digits match another <pre>expression, then the end device starts digit suppression again.

After digit suppression begins, it might become clear that a match willnot occur. For example, take the expression“<regex><pre>*8</pre>xxx[2-9]xxxxxx</regex>”. At the point the endpointreceives “*8”, it will stop sending digits. Let us say that the nextthree digits from the user are “408”, which match the “xxx” part of thepattern. If the next digit is a zero or one, the pattern will not match,meaning that there is no mechanism for re-enabling the sending of digitson the media connection.

Applications should be very careful to indicate suppression only whenthey are fairly sure the user will enter a digit string that will matchthe regular expression. In addition, applications should deal withsituations such as no-match or time-out. This is because the endpointwill hold digits, which will have obvious user interface issues in thecase of a failure. Also, it is very important for the endpoint to have asensible inter-digit timer. This is because an errant dot (“.”) maysuppress digit sending forever. Reasonable values are on the order offour seconds.

One unique aspect of the presently disclosed system is the handling ofquarantined key presses. A quarantined key press is an event that doesnot yet match a regular expression. The system often quarantines keypresses between the time of a notification and, particularly in the caseof one-shot subscriptions, the receipt of a new subscription.

If the user presses a key not matched by the <regex> tags, the end pointdevice discards the key press from consideration against the current orfuture KPML messages. However, once there is a match, the end pointdevice quarantines any key presses the user entered subsequent to thematch. This behavior allows for applications to only receive digits thatinterest them.

Before the receipt of the first subscription, the end point device doesnot normally quarantine key press events. This can create a racecondition. Namely, the end point device can establish a session and havekey press events occur before the end point device receives the firstsubscription. If this is of concern, the end point device can beprovisioned to quarantine all key press events, or the end point devicecan be signaled at session establishment time that there will be asubscription. In the SIP environment, the first KPML subscription can beincluded as a separate MIME body part to the initial INVITE message.

At some point in time, the end point device has an indication toquarantine digits, either because of provisioning, explicit signaling,or receiving a subscription. That subscription will be associated with aSIP dialog or dialog/id pair. In the case of explicit provisioning orexplicit signaling, there will be an implicit subscription on the INVITEdialog. In the case of a SUBSCRIBE request, the subscription isassociated with the given SUBSCIBE-initiated dialog. Again, the endpoint device considers a SUBSCRIBE request with a unique “id” tag to bea new subscription for quarantine purposes.

The importance of separate subscriptions comes from the per-subscriptionquarantine of key presses. This enables application consistency. Theapplication will get all key presses, in temporal order, which it isinterested in, without interference from the subscriptions of otherapplications.

It could be required that the current request determine the quarantinepolicy for post -notification processing. This makes sense when allsubscriptions come from a single application, which presumably is awareof its own quarantine needs. However, such an approach is not acceptablefor a system that must support multiple independent applications, eachpotentially unaware of the others. Each request must set its ownquarantine policy for the key presses already buffered.

Requests can explicitly flush the per-subscription key press buffer whenthe end point device loads a new KPML request on the given subscriptionby specifying the <flush>yes</flush> entity in the <pattern> tag. Also,requests can explicitly flush digits in the current subscription'sbuffer that have already been matched or considered by othersubscriptions by specifying the <flush>others</flush> entity in the<pattern> tag.

FIG. 5 shows a single key press buffer 56 for recording all key presses,with per-stream indices or pointers 58, 60, and 62 into the key pressbuffer indicating where in the buffer the stream is. Examples are givento illustrate operation of this buffer 56.

Consider the pattern <regex>xxxxxxxx</regex> specified bysubscription 1. In this case, the buffered digits 12345678 match thepattern. Thus, the pattern succeeds, the end point device reports thematch, and the pointer 58 is subsequently positioned at buffer location64.

Next, consider the pattern <regex>x{10}</regex>. In this case, thecollected digits 123456789# will never match the pattern, because “#” isnot a digit and will not match ‘x’. The pattern fails, the end pointdevice reports the failure, and the pointer 58 is subsequentlypositioned at buffer location 66.

Finally, consider the pattern <regex>***</regex>. In this case, the endpoint device scans the buffer until the first*at position 66, which isthe first character that matches the pattern, and thus bypasses thefirst 10 key presses entered. The pattern then succeeds, the end pointdevice reports the match, and the pointer 58 will be positioned atbuffer location 68.

Now consider what happens if a request specifies <flush>others</flush>and a <regex>x{7}</regex>. In -this case, other streams have seen keypresses up to position 68, the position of buffer pointer 62. Thus theend point device moves the buffer pointer 58 to position 68 and thenstarts matching key presses. In this example, the pattern fails, asthere are only three digits before a non-digit key (the long #). Becausethe end point device has considered all key presses between thepositions pointed to by pointers 58 and 60, the end point device freesthe memory in the buffer between those positions.

The key press buffer can be made quite large, for example by employing alarge secondary storage device in the form of a hard disk. The end pointdevice can put parts of the key press buffer onto the secondary storagedevice, keeping more recently referenced buffered key presses in mainmemory. This operation is accomplished in a straightforward manner usingconventional virtual memory techniques.

Even with a large secondary storage device, it is possible to fill thebuffer completely, especially if a large number of media streams arebeing monitored and if many streams have multiple subscriptions. Toaddress this problem, the end point device can use a circular buffer.When the end-of-buffer pointer will overlap a given subscription'spointer, the subscription's pointer is set to the next subscriptionpointer, in increasing time order. The end point device also sets a“forced_flush” indicator for the subscription pointer, which is includedin the end point device's report on a match or failure and thensubsequently cleared.

Note that using a circular buffer is superior to having key presses ageout of the buffer. This is because there is no reason to remove keypress history if the memory is available. Likewise, under load, thebuffer may still overflow if requests do not free digits off of thebuffer fast enough. Nonetheless, the presently disclosed technique maybe used with non-circular buffers as well.

When the user enters key press(es) that match a <regex> tag, the endpoint device will issue a report. After reporting, the end point deviceterminates the KPML session unless the subscription has a persistenceindicator. If the subscription does not have a persistence indicator,the end point device sets the state of the subscription to “terminated”in the NOTIFY report. If the requestor desires to collect more digits,it must issue a new request. If the subscription has a persistenceindicator, then the device uses the same <pattern> to match againstfuture key presses.

KPML reports have two mandatory attributes, code and text. Theseattributes describe the state of a KPML interpreter on the end device.In the preferred embodiment, the SIP state of the subscription, such as“active” or “terminated”, is also a protocol parameter. If one were touse a transport other than SIP that does not convey the subscriptionstate, the subscription state must be one of the attributes of the KPMLreport.

Note that the KPML code is not necessarily related to the SIP resultcode. An important example is when a legal SIP subscription request getsa normal SIP 200 OK followed by a NOTIFY, but there is something wrongwith the KPML request. In this case, the NOTIFY would include the KPMLfailure code in the KPML report. Note that from a SIP perspective, theSUBSCRIBE and NOTIFY were successful. Also, if the KPML failure is notrecoverable, the end device will most likely set the Subscription-Stateto terminated. This lets the SIP machinery know the subscription is nolonger active.

If a pattern matches, the end point device emits a KPML report. Sincethis is a success report, the code is “200” and the text is “OK”. TheKPML report includes the actual digits matched in the digit attribute.The digit string uses the conventional characters ‘*’ and ‘#’ for starand octothorpe, respectively. The KPML report also includes the tagattribute if the regex that matched the digits had a tag attribute. Ifthe subscription requested digit suppression and the end devicesuppressed digits, the suppressed attribute indicates “true”. Thedefault value of suppressed is “false”. Embodiments of the device mayhave a datum indicating if the device terminated digit collection due tothe receipt of the Enter Key sequence in the KPML report. It may bedesirable to omit this datum, as many applications do not need thisinformation.

Example 9 shows a typical KPML response. This is an example of aresponse to the request shown in Example 4.

<?xml version=“1.0” encoding=“UTF-8”?> <kpmlxmlns=“urn:ietf:params:xml:ns:kpml” xmlns:xsi=“http://www.w3.org/2001/XMLSchema-instance” xsi:schemaLocation=“urn:ietf:params:xml:ns:kpml kpml.xsd” version=“1.0”>   <response code=“200” text=“OK” tag=“ld”digits=“17035551212”/> </kpml>

EXAMPLE 9 Sample Response

There are a few circumstances in which the end point device will emit ano match report. They are an immediate NOTIFY in response to SUBSCRIBErequest (no digits detected yet), a request for service not supported bythe end device, or a failure of a digit map to match a string (timeout).Preferably, the NOTIFY in response to a SUBSCRIBE request has no KPML ifthere are no matching quarantined digits.

Example 10 shows a typical time-out response. Note the device reportsthe digits collected up to the timeout in the digits attribute of theresponse tag.

<?xml version=“1.0” encoding=“UTF-8”?> <kpmlxmlns=“urn:ietf:params:xml:ns:kpml” xmlns:xsi=“http://www.w3.org/2001/XMLSchema-instance” xsi:schemaLocation=“urn:ietf:params:xml:ns:kpml kpml.xsd” version=“1.0”>   <response code=“423” text=“Timer Expired”digits=“1703555”/> </kpml>

EXAMPLE 10 Sample Time-Out Response

If there are quarantined digits in the SUBSCRIBE request that match apattern, then the NOTIFY message in response to the SUBSCRIBE requestincludes the appropriate KPML document.

Key presses collected using the disclosed method can contain sensitiveinformation, such as PIN codes, credit card numbers, or other personalinformation. Thus notifications should be secure, integrity checked, andnot accessible to unauthorized parties. Likewise, the end point deviceneeds to authenticate subscriptions and make sure the subscriber isauthorized to access the key press information. Moreover, subscriptionsalso need cryptographic integrity guarantees and need protection againstspoofing and man-in-the-middle attacks.

A technology known as Transport Layer Security (TLS) can be used fortransport security, and a separate technology known as S/MIME can beused for the SUBSCRIBE and NOTIFY methods to guarantee authentication,integrity, and non-repudiation.

Example 10 is an example of a schema that embodies the facets of thepreferred embodiment as described herein. A graphical representation ofthis schema is in FIG. 6.

<?xml version=“1.0” encoding=“UTF-8”?> <xs:schematargetNamespace=“urn:ietf:params:xml:ns:kpml” xmlns=“urn:ietf:params:xml:ns:kpml” xmlns:xs=“http://www.w3.org/2001/XMLSchema” elementFormDefault=“qualified”  attributeFormDefault=“unqualified”> <xs:element name=“kpml”>   <xs:annotation>    <xs:documentation>IETFKeypad Markup     Language</xs:documentation>   </xs:annotation>  <xs:complexType>    <xs:choice>     <xs:element name=“request”>     <xs:complexType>       <xs:sequence>        <xs:elementname=“stream” type=“xs:string”         minOccurs=“0”/>       <xs:element name=“pattern”>         <xs:complexType>         <xs:sequence>           <xs:element name=“flush” minOccurs=“0”>           <xs:complexType>             <xs:simpleContent>             <xs:extension base=“xs:string”/>            </xs:simpleContent>            </xs:complexType>          </xs:element>           <xs:element name=“enterkey”minOccurs=“0”>            <xs:complexType>            <xs:simpleContent>              <xs:extensionbase=“xs:string”/>             </xs:simpleContent>           </xs:complexType>           </xs:element>          <xs:element name=“regex”           maxOccurs=“unbounded”>           <xs:complexType mixed=“true”>             <xs:sequence>             <xs:element name=“pre” minOccurs=“0”>              <xs:complexType>                <xs:simpleContent>                <xs:extension base=“xs:string”/>               </xs:simpleContent>               </xs:complexType>             </xs:element>             </xs:sequence>            <xs:attribute name=“tag” type=“xs:string”             use=“optional”/>            </xs:complexType>          </xs:element>          </xs:sequence>          <xs:attributename=“persistent” type=“xs:boolean”           use=“optional”/>         <xs:attribute name=“interdigittimer”          type=“xs:integer”          use=“optional”/>         <xs:attribute name=“criticaldigittimer”          type=“xs:integer”           use=“optional”/>         <xs:attribute name=“extradigittimer”          type=“xs:integer”           use=“optional”/>         <xs:attribute name=“longtimer”           type=“xs:integer”          use=“optional”/>          <xs:attribute name=“longrepeat”          type=“xs:boolean”           use=“optional”/>        </xs:complexType>        </xs:element>       </xs:sequence>     </xs:complexType>     </xs:element>     <xs:elementname=“response”>      <xs:complexType>       <xs:attribute name=“code”type=“xs:string”        use=“required”/>       <xs:attribute name=“text”type=“xs:string”        use=“required”/>       <xs:attributename=“suppressed” type=“xs:boolean”        use=“optional”/>      <xs:attribute name=“forced_flush” type=“xs:boolean”       use=“optional”/>       <xs:attribute name=“digits”type=“xs:string”        use=“optional”/>       <xs:attribute name=“tag”type=“xs:string” use=“optional”/>      </xs:complexType>    </xs:element>    </xs:choice>    <xs:attribute name=“version”type=“xs:string” use=“required”/>   </xs:complexType>  </xs:element></xs:schema>

EXAMPLE 10 Representative KPML Schema

Although in the foregoing description, the particular form of user inputconstitutes key presses from a telephone keypad, it will be appreciatedthat the disclosed system and method are also usable with other forms ofuser input and other devices. For example, the user input may constitutecertain patterns of speech that can be recognized by speech recognitionhardware/software and then made the subject of subscriptions andnotifications as described above. The disclosed system and method mayalso be used with devices such as personal computers (PCs), personaldigital assistants (PDAs), or other devices capable of accepting userinput in the form of touches or strokes on a screen using a finger or astylus. Additionally, the “user” generating the input need not be ahuman user, as in the case of a computer or other device generating keypress tones or other user input in a manner mimicking the behavior of ahuman user.

Remotely Controlling a Device via a Communication Device

FIG. 7 is a block diagram of a system for remotely controlling one ormore premises devices, such as a television 700, a refrigerator 702, amedia center 704, and/or other type of household, office or other typeof devices, via a communication device. Other exemplary premises devices(not shown) that can be remotely controlled include an air-conditioner,a heater, a stove or other cooking appliance, a camera, an answeringmachine, a surveillance security system, and a personal computer. Theremotely controlled devices 700-704 are connected to a local network706, such as an Internet protocol (IP) local area network (LAN), forexample an Ethernet network.

The local network 706 can be wired, wireless or a combination thereof.Many homes and offices are equipped with such local networks. AlthoughFIG. 7 shows a single local network 706, the local network can include acombination of networks. For example, the local network 706 can includeone or more short-range wireless networks, such as Bluetooth, 802.11b,802.11g, etc., interconnected via appropriate bridges, routers, etc.Links between the remotely controlled devices 700-704 and the localnetwork 706 can be wired or wireless.

Several non-limiting examples of communication devices are also shown inFIG. 7 and discuss the following paragraphs. The communication devicecan be a wired or wireless (such as cellular) telephone 708 or 710connected to a land or mobile telephone network 712. If signals from thetelephone 708 or 710 are carried over a conventional (i.e.,non-packet-switched) telephone network, a media gateway, integratedaccess device (IAD) or other suitable telephone network gateway(collectively referred to as a media gateway) 714 is used to converttelephony signals, such as signaling (call setup, etc.) and sound (TDM,etc.) signals carried over the conventional telephone network, to andfrom telephony signals carried over an package-switched network, such asthe local network 706, as is well known in the art. However, forpurposes of the present invention, only a signaling path needs to beestablished, as will be described in more detail below. As used herein,“signaling” or “telephony signaling” means setup and control, such astear-down, of a call, as distinct from the media (such as voice) signalsof a call. Thus, the media gateway 714 can, but need not, be a subset ofa conventional media gateway. The media gateway 714 can be locatedwithin the telephone network 712 or outside the telephone network, suchas on the same premises as the remotely controlled devices 700-704, oranywhere between the telephone network and the premises.

The remotely controlled premises devices 700-704 are external to, andnot part of, the telephone network 712. For example, the remotelycontrolled devices 700-704 are not telephone network elements, such asswitches, intelligent peripherals or other telephone network elementsthat respond to signaling information, such as dialed telephone numbers.

The communication device can be an Internet telephone, such as a voiceover IP (VoIP) telephone 716 connected directly (as shown) orindirectly, such as via a router (not shown), to the Internet 718. Anexample of a suitable Internet telephone 716 is a telephone thatoperates according the session initiation protocol (SIP). In the case ofan Internet telephone 716, a media gateway is generally not necessary,because the signals from the Internet telephone are generally compatiblewith the local network 706. The local network 706 is connected to theInternet or another wide area network 718 via a router or other suitabledevice 720 to receive packets from the Internet telephone 716. A portionof the call can be carried over the Internet, another wide area network,a telephone network or a combination thereof.

The communication device can be a suitably configured personal computer722 that is directly or indirectly connected to the Internet 718. Thepersonal computer 722 executes software to enable a user to presssimulated dial pad buttons and to place telephone calls over theInternet 718 in a manner similar to that used by the Internet telephone716. Optionally, i.e., if the remotely controlled devices 700-704 are torespond to speech commands, the personal computer 722 includes amicrophone (not shown). In addition, if voice prompts are to be playedto the user, a personal computer 722 includes a speaker or headphones(not shown).

The communication device can be an analog telephone 724 connected via anLAD 726 to the Internet 718. A suitable IAD is available from Linksys, adivision of Cisco Systems, Inc., Irvine, Calif. under the tradenameLinksys WRT54GP2 Wireless-G Broadband Router. The analog telephone 724can be located anywhere access to the Internet 718 is available. Asnoted above with respect to the media gateway 714, the IAD 726 convertssignals from the analog telephone 724 to and from signals that can betransported over the Internet 718 to place telephone calls.

The communication devices discussed above are generally not located onthe same premises as the remotely controlled devices 700-704. Thesecommunication devices, particularly the wireless telephone 710, can,however, also be advantageously used on the premises to control theremotely controlled devices 700-704. For example, the wireless telephone710 can be used to: change the volume played or the channel displayed bythe television 700; command the refrigerator 702 to dispense a beverage;or command the media center 704 to play a musical selection in anidentified room of the premises.

Communication devices that are co-located with the remotely controlleddevices 700-704 can also be used to remotely control the devices700-704. For example, a local Internet telephone 728 connected to thelocal network 706 can be used to control the remotely controlled devices700-704. In addition, a local analog telephone 730, connected via an LAD732 to the local network 706, can control the remote controlled devices700-704.

A controller 734 is connected to the local network 706 via a wired orwireless link. The controller 734 contains hardware and/or software tocontrol operations of the remotely controlled devices 700-704 inresponse to user interactions with one of the communication devices 708,710, 716, 722, 724, 728 or 730. The controller 734 communicates with theremotely controlled device 700-704 via the local network 706 to issuecommands to the remotely controlled device and, optionally, to obtainstatus information from the remotely controlled device. The controller734 can include a memory storing instructions and data and a processorto execute the instructions and to access and store the data, therebyperforming the functions described herein. Alternatively, the controller734 can be implemented with an application-specific integrated circuit(ASIC), field -programmable gate array (FPGA) or other suitablehardware, software or combination thereof.

In one embodiment, the controller 734 is separate from the remotelycontrolled devices 700 -704, as shown in FIG. 7. In another embodiment(not shown), the controller 734 is included in one or each of theremotely controlled devices 700-704. If a controller 734 is included inone of the remotely controlled devices 700-704, the controller cancontrol only the device in which it is included, or the controller cancontrol other devices 700-704 by communicating with the other devicesvia the local network 706.

The controller 734 also communicates via a telephony signaling path andaccording to a protocol, such as SIP, with the communication device orwith another unit located between the communication device and thecontroller 734. The communication device places a telephone call to thepremises or directly to the controller 734. Alternatively, thecontroller 734 places a telephone call to the communication device. Ineither case, a voice path need not be established from the communicationdevice to the controller 734. Instead, a telephony signaling path isestablished, and information about user interactions with thecommunication device during the call, such as dial pad key presses, aresent over the signaling path to the controller 734.

The controller 734 interprets the user interactions and issuescorresponding commands to the remotely controlled devices 700-704. Forexample, pressing the star “*” key on the telephone causes thecontroller 734 to increase the volume of audio played by the television700, and pressing a sequence of digit keys followed by the pound “#” keycauses the controller 734 to change the channel displayed by thetelevision 700 to a channel identified by the sequence of pressed digitkeys. If more than one remotely controlled device 700-704 is controlledby a single controller 734, the user interaction includes one or morebutton presses to identify which remotely controlled device(s) is(are)the target(s) of the command. In one embodiment, each command includesan identification of the target remotely controlled device(s) 700-704.In another embodiment, the controller 734 accepts a command to identifyone or more of the remotely controlled devices 700 -704, therebyestablishing a “context,” and subsequent commands are interpreted asbeing directed to the selected device(s) until a different context isestablished.

If the communication device, such as the Internet telephone 716 or 728or the personal computer 722, is capable of communicating according tothe signaling protocol, the controller 734 communicates directly withthe communication device. In one embodiment, the Internet telephone 716or 728 or the personal computer 722 places a call to the controller's734 address. This address can indicate which remotely controlled device700-704 is to be controlled. An example address isSIP:MyTV@EricsHouse.Adelphia.net. Once the call is established,information about user interactions with the communication device, suchas keypad button presses, strokes on a touch -sensitive screen, etc.,are sent to the controller 734 as packets in the signaling path. Novoice path needs to be established between the communication device inthe controller 734. Consequently, the controller 734 need not includeDTMF detection hardware or software, nor a protocol stack to supportRTP.

During a voice call, voice signals are exchanged between SIP or similardevices as a series of compressed (encoded) samples, such as accordingto RTP. When a SIP or similar called device receives an invitation toparticipate in a call, the called device responds with a list ofencoding types the called device is prepared to accept. Essentially,this list represents the types of compressor-decompressors (CODECs)included in the called device. In one embodiment, when the controller734 receives an invitation to participate in the call, the controller734 responds with a message indicating that the controller 734 is notprepared to accept any type of compressed signals. Consequently, noaudio path is established to the controller 734. Alternatively, thecalling communication device can request setup of the call without anaudio path.

On the other hand, as noted above, if a communication device, such as a“plain old telephone service” (POTS) telephone 724 or 730, is notcapable of communicating according to the signaling protocol, thecommunication device is connected to an IAD 726 or 732, which supportssuch a signaling protocol and performs appropriate conversions. In thiscase, the IAD 726 or 732 performs DTMF detection. Thus, if the userpresses one or more key pad buttons, the IAD 726 or 732 detects thegenerated DTMF tones and sends messages in packets over the signalingchannel of the Internet 718 and/or the local network 706 to thecontroller 734 to notify the controller of the user interactions withthe communication device.

Similarly, if a telephone 708 or 710 or other communication device isconnected to the telephone network 712, and a call placed by such acommunication device is carried over the telephone network 712 such thatinformation about user interactions is carried only in-band, the call isrouted through the media gateway 714. As noted, the media gateway 714can be located within the telephone network 712, on the premises withthe remotely controlled devices 700, 702, 704 or elsewhere. The mediagateway 714 performs DTMF detection and sends messages in packets overthe signaling channel of the telephone network 712 and/or the localnetwork 706 to the controller 734 to notify the controller of the userinteractions with the communication device. If several telephone numbersare used for several controlled devices 700, 702, 704, or if severaltelephone numbers are used for voice communication, fax, controllingdevices, and/or other purposes, the media gateway 714 can use dialednumber identification service (DNIS) information provided by thetelephone network 712 to identify the purpose of a call or to identify aparticular device that is to be controlled. If a device is to becontrolled, the media gateway can pass this information to thecontroller 734.

Thus, the communication device can control the remotely controlleddevice 700-704 without the need to establish a voice path, and withoutrequiring a DTMF detector or RTP protocol stack in the controller 734.Instead, the communication device places a call. The call isestablished, including establishing a telephony signaling path, such asover at least part of the telephone network 712, the Internet 718 and/orthe local network 706, to carry at least one telephony signaling packetgenerated as a result of the user interaction with the communicationdevice during the call, and the communication device controls theremotely controlled device solely via the at least one telephonysignaling packet carried over the telephony signaling path.

Optionally, an audio path is established from the controller 734 to thecommunication device so that the controller can play one or more audioprompts to the user. This audio path extends over a portion of the localnetwork 706, the telephone network 712, and/or the Internet 718, asappropriate, depending on the location of the communication deviceand/or an IAD or media gateway (if used). However, the controller 734need not include a full RTP protocol stack to support the playing ofaudio prompts. For example, the controller 734 need not include an RTPprotocol stack for incoming audio, unless the controller 734 is alsocontrollable by speech. (If the controller 734 is controllable byspeech, the controller includes appropriate speech recognition hardwareand/or software.) In addition, the controller 734 can include simplifiedRTP support for outgoing prompts. For example, the controller 734 storesprompts in a format, such as in a file according to G.711, suitable forsending to a rendering device. Playing the prompt simply involvessending the contents of the file as a series of RTP packets withmonotonically increasing sequence numbers in the RTP headers.Furthermore, the controller 734 can ignore feedback, such as feedbackregarding network congestion.

To prevent unauthorized control of the devices 700-704, the controller734 can employ an authentication mechanism, such as requiring the userto enter a passcode. For example, the user can enter the passcode as asequence of key presses, and the controller 734 can check the passcoderepresented by the signaling packets sent as a result of the keypresses. Alternatively, the Internet telephone 716 or 728 can beconfigured with authentication information. In this case, the Internettelephone 716 or 728 provides this authentication information to thecontroller 734, thereby obviating the need for the user to identify orauthenticate him/herself. Advantageously, the user can disconnect theInternet telephone 728, remove it from the premises, and reconnect theInternet telephone 728 anywhere an Internet connection is available. Inthis case, the controller 734 continues to identify the Internettelephone 728 and recognize the user as being authenticated.Consequently, the Internet telephone 728 becomes a physical “token,” andpossession of the token enables the user to control the remotelycontrolled devices 700-704 without entering a passcode.

Similarly, the IAD 732 can be configured with authenticationinformation. In this case, a user of the local POTS telephone 730 neednot enter a passcode to control the remotely controlled devices 700-704.

The media gateway 714 typically cannot be configured with authenticationinformation. However, the media gateway 714 receives calleridentification information, and the media gateway 714 can pass thatidentification information to the controller 734.

In another embodiment, if the mobile telephone 710 includes a subscriberidentity module (SIM) (not shown), an IP multimedia subsystem (IMS) (notshown) can interrogate the SIM to ascertain the identity of the user ofthe mobile telephone 710, and the IMS can then provide this identityinformation to the controller 734.

The controller 734 uses the Key Press Markup Language (KPML), asdescribed above, or another suitable protocol to request notificationfrom the communication device, IAD or media gateway, as appropriate, ofuser interactions with the communication device. Thus, the controller734 corresponds to the application server 46 or 48 or to the aggregationserver 54 shown in FIG. 4. Similarly, the communication device (if thecommunication device is capable of SIP signaling) or the IAD or mediagateway or other device that receives DTMF signals from thecommunication device corresponds to the end point 50 in FIG. 4. If thecontroller 734 controls several remotely controlled devices 700-704, thecontroller can appear as several application servers, one correspondingto each of the remotely controlled devices. Furthermore, as noted above,other application servers (such as other controllers (not shown) forcontrolling remotely controlled devices or other application servers(not shown) unrelated to remotely controlled devices) can register withthe end point to receive notifications of user interactions with thecommunication device.

While the invention is described through the above-described exemplaryembodiments, it will be understood by those of ordinary skill in the artthat modifications to, and variations of, the illustrated embodimentsmay be made without departing from the inventive concepts disclosedherein. Moreover, while the preferred embodiments are described inconnection with various illustrative data structures, one skilled in theart will recognize that the system may be embodied using a variety ofdata structures. Accordingly, the invention should not be viewed aslimited, except by the scope and spirit of the appended claims.

1. A method of remotely controlling a remotely controlled device via acommunication device, the communication device being communicablycoupled to a network, the remotely controlled device being external tothe network, the method comprising the steps of: generating asubscription message by a controller communicably coupled to thenetwork, the subscription message conforming to a session based protocoland specifying a pattern of user input upon whose occurrence thecontroller is to be notified; sending the subscription message from thecontroller to the communication device over the network using thesession based protocol; monitoring, at the communication device, a userinput for the occurrence of the specified pattern of user input in thesubscription message; responsive to a user interaction with thecommunication device that includes the specified pattern of user input,notifying the controller of the occurrence of the specified pattern ofuser input, including: placing, by the communication device, a call tothe controller over the network; establishing the call, includingestablishing a telephony signaling path between the communication deviceand the controller, the communication device and the controller beingoperative to communicate with one another over the telephony signalingpath using the session based protocol; generating a plurality oftelephony signaling packets containing a notification of the userinteraction with the communication device, the notification conformingto the session based protocol, the telephony signaling path beingoperative to carry the plurality of telephony signaling packetscontaining the notification of the user interaction with thecommunication device; and sending the plurality of telephony signalingpackets containing the notification of the user interaction with thecommunication device from the communication device to the controllerover the telephony signaling path using the session based protocol;responsive to the notification contained in the plurality of telephonysignaling packets, controlling the remotely controlled device by thecontroller; and otherwise, responsive to a user interaction with thecommunication device that includes a pattern of user input that isdifferent from the specified pattern of user input, refraining fromnotifying the controller of the user interaction with the communicationdevice, wherein the subscription message optionally includes apersistence indicator indicating that the communication device is tonotify the controller of each of multiple occurrences of the specifiedpattern of user input in the subscription message, and wherein themethod further comprises, at the communication device: determiningwhether the persistence indicator is included in the subscriptionmessage; if the persistence indicator is included in the subscriptionmessage, repeating the monitoring of the user input and the notifying ofthe controller for at least one subsequent occurrence of the specifiedpattern of user input in the subscription message, and if thepersistence indicator is not included in the subscription message,ceasing the monitoring of the user input upon a first notification ofthe controller that the specified pattern of user input has occurred inthe subscription message.
 2. The method of claim 1, wherein establishingthe call comprises avoiding establishing an audio path for the call. 3.The method of claim 1, further comprising: establishing an audio path tothe communication device; and sending at least one audio prompt via theaudio path to the communication device.
 4. The method of claim 3,wherein establishing the audio path comprises establishing at least aportion of the audio path over the network.
 5. The method of claim 3,wherein the network includes a public wide area network, and whereinestablishing the audio path comprises establishing at least a portion ofthe audio path over the public wide area network.
 6. The method of claim3, wherein establishing the audio path comprises establishing at least aportion of the audio path over the Internet.
 7. The method of claim 3,wherein the network includes a private local area network, and whereinestablishing the audio path comprises establishing at least a portion ofthe audio path over the private local area network.
 8. The method ofclaim 1, wherein the network includes a telephone network, and whereinestablishing the telephony signaling path comprises establishing atleast a portion of the telephony signaling path over the telephonenetwork.
 9. The method of claim 1, wherein the network includes a publicwide area network, and wherein establishing the telephony signaling pathcomprises establishing at least a portion of the telephony signalingpath over the public wide area network.
 10. The method of claim 1,wherein establishing the telephony signaling path comprises establishingat least a portion of the telephony signaling path over the Internet.11. The method of claim 1, wherein the network includes a private localarea network, and wherein establishing the telephony signaling pathcomprises establishing at least a portion of the telephony signalingpath over the private local area network.
 12. The method of claim 1,wherein establishing the telephony signaling path comprises establishingat least a portion of the telephony signaling path between thecommunication device and the controller, the controller being externalto the remotely controlled device.
 13. The method of claim 1, whereinthe network includes a telephone network, and wherein establishing thetelephony signaling path comprises establishing at least a portion ofthe telephony signaling path between an element within the telephonenetwork and the controller, the controller being external to theremotely controlled device.
 14. The method of claim 1, wherein thenetwork includes a telephone network, and wherein establishing thetelephony signaling path comprises establishing at least a portion ofthe telephony signaling path between a telephone network gateway and thecontroller, the controller being external to the remotely controlleddevice.
 15. The method of claim 1, wherein establishing the telephonysignaling path comprises establishing at least a portion of thetelephony signaling path between an integrated access device and thecontroller, the controller being external to the remotely controlleddevice.
 16. The method of claim 1, wherein the communication device isan analog telephone.
 17. The method of claim 1, wherein thecommunication device is a VoIP telephone.
 18. The method of claim 1,wherein the communication device is a personal computer.
 19. The methodof claim 1, wherein: the communication device comprises atouch-sensitive screen; and the user interaction comprises at least onetouch or stroke on the touch-sensitive screen.
 20. The method of claim1, wherein the user interaction comprises at least one key press. 21.The method of claim 1, wherein the user interaction comprises speech.22. The method of claim 1, wherein the user interaction is provided by ahuman user.
 23. The method of claim 1, wherein the user interaction isprovided by a computer.
 24. The method of claim 1 wherein the sessionbased protocol is the Session Initiation Protocol (SIP).
 25. The methodof claim 1 wherein the generating of the subscription message by thecontroller includes generating the subscription message by thecontroller comprising an application server.
 26. The method of claim 25wherein the generating of the subscription message includes generating,by the application server, the subscription message using apredetermined key press markup language.
 27. A system for remotelycontrolling a remotely controlled device, comprising: a network; acontroller communicably connected to the network, the controller beingoperative to control the remotely controlled device, wherein theremotely controlled device is external to the network; and acommunication device communicably connected to the network, wherein thecontroller is operative: to generate a subscription message conformingto a session based protocol and specifying a pattern of user input uponwhose occurrence the controller is to be notified; and to send thesubscription message to the communication device over the network usingthe session based protocol, wherein the communication device isoperative: to monitor a user input for the occurrence of the specifiedpattern of user input specified in the subscription message; responsiveto a user interaction with the communication device that includes thespecified pattern of user input, to notify the controller of theoccurrence of the specified pattern of user input, including: to place acall to the controller over the network, thereby establishing atelephony signaling path between the communication device and thecontroller, the communication device and the controller being operativeto communicate with one another over the telephony signaling path usingthe session based protocol; to generate a plurality of telephonysignaling packets containing a notification of the user interaction withthe communication device, the notification conforming to the sessionbased protocol, the telephony signaling path being operative to carrythe plurality of telephony signaling packets containing the notificationof the user interaction with the communication device; and to send theplurality of telephony signaling packets containing the notification ofthe user interaction with the communication device to the controllerover the telephony signaling path using the session based protocol,wherein, responsive to the notification contained in the plurality oftelephony signaling packets, the controller is further operative tocontrol the remotely controlled device, and wherein the communicationdevice is further operative, otherwise, in response to a userinteraction with the communication device that includes a pattern ofuser input that is different from the specified pattern of user input,to refrain from notifying the controller of the user interaction withthe communication device, wherein the subscription message optionallyincludes a persistence indicator indicating that the communicationdevice is to notify the controller of each of multiple occurrences ofthe specified pattern of user input in the subscription message, andwherein the communication device is further operative: to determinewhether the persistence indicator is included in the subscriptionmessage; if the persistence indicator is included in the subscriptionmessage, to repeat the monitoring of the user input and the notifying ofthe controller for at least one subsequent occurrence of the specifiedpattern of user input in the subscription message, and if thepersistence indicator is not included in the subscription message, tocease the monitoring of the user input upon a first notification of thecontroller that the specified pattern of user input has occurred in thesubscription message.
 28. The system of claim 27, wherein, to place thecall, the communication device is operative to establish a telephonysignaling path over the network for the call and to avoid establishingan audio path over the network for the call.
 29. The system of claim 27,wherein the controller is operative to: establish an audio path over thenetwork to the communication device; and play at least one audio promptover the audio path.
 30. The system of claim 27, wherein the networkincludes at least a portion of the Internet.
 31. The system of claim 27,wherein the network includes at least a portion of a telephone network.32. The system of claim 27, wherein the network includes at least aportion of the Internet and a telephone network.
 33. The system of claim27, wherein the communication device comprises a VoIP telephone.
 34. Thesystem of claim 27, wherein the communication device comprises apersonal computer.
 35. The system of claim 27, wherein the communicationdevice comprises a touch-sensitive screen and the user interactioncomprises at least one touch or stroke on the touch-sensitive screen.36. The system of claim 27, wherein the user interaction comprises atleast one key press.
 37. The system of claim 27, wherein the userinteraction comprises speech.
 38. The system of claim 27, wherein thenetwork includes a local network, and wherein the controller isoperative to control the remotely controlled device via the localnetwork.
 39. The system of claim 27 wherein the session based protocolis the Session Initiation Protocol (SIP).
 40. The system of claim 27wherein the controller comprises an application server.
 41. The methodof claim 40 wherein the application server is operative to generate thesubscription message using a predetermined key press markup language.42. A system for remotely controlling a remotely controlled device,comprising: a network; a controller communicably connected to thenetwork, the controller being operative to control the remotelycontrolled device, the remotely controlled device being external to thenetwork; a communication device communicably connected to the network;and a gateway having an associated subscription device, the gateway andthe subscription device being communicably connected between thecommunication device and the controller, the gateway, the subscriptiondevice, and the controller being operative to communicate with oneanother using a session based protocol, wherein the controller isoperative: to generate a subscription message conforming to the sessionbased protocol and specifying a pattern of user input upon whoseoccurrence the controller is to be notified; and to send thesubscription message to the subscription device over the network usingthe session based protocol, wherein the subscription device isoperative: to monitor a user input at the communication device for theoccurrence of the pattern of user input specified in the subscriptionmessage; and responsive to a user interaction with the communicationdevice that includes the specified pattern of user input, to generate anotification of the user interaction with the communication device, thenotification conforming to the session based protocol, wherein,responsive to the user interaction with the communication device thatincludes the pattern of user input, the communication device isoperative to notify the controller of the occurrence of the specifiedpattern of user input, including: to place a call to the controller overthe network; to generate at least one signal relating to the userinteraction with the communication device; and to send the at least onesignal in-band to the gateway over the network; wherein the gateway isfurther operative: to receive the at least one signal from thecommunication device; to receive the notification of the userinteraction from the subscription device; responsive to receiving the atleast one signal from the communication device and the notification ofthe user interaction from the subscription device, to generate aplurality of telephony signaling packets containing the notification ofthe user interaction; and to send the plurality of telephony signalingpackets containing the notification of the user interaction out-of-bandto the controller using the session based protocol, wherein, responsiveto the notification of the user interaction contained in the pluralityof telephony signaling packets, the controller is further operative tocontrol the remotely controlled device, and wherein the subscriptiondevice is further operative, otherwise, in response to a userinteraction with the communication device that includes a pattern ofuser input that is different from the specified pattern of user input,to refrain from notifying the controller of the user interaction withthe communication device, wherein the subscription message optionallyincludes a persistence indicator indicating that the subscription deviceis to notify the controller of each of multiple occurrences of thespecified pattern of user input in the subscription message, and whereinthe subscription device is further operative: to determine whether thepersistence indicator is included in the subscription message; if thepersistence indicator is included in the subscription message, to repeatthe monitoring of the user input and the notifying of the controller forat least one subsequent occurrence of the specified pattern of userinput in the subscription message, and if the persistence indicator isnot included in the subscription message, to cease the monitoring of theuser input upon a first notification of the controller that thespecified pattern of user input has occurred in the subscriptionmessage.
 43. The system of claim 42, wherein, to generate the pluralityof telephony signaling packets, the gateway is operative to establish atelephony signaling path and to avoid establishing an audio path. 44.The system of claim 42, wherein the controller is operative to:establish an audio path to the gateway; and play at least one audioprompt over the audio path.
 45. The system of claim 42, wherein thenetwork includes a local network, and wherein the controller isoperative to control the remotely controlled device via the localnetwork.
 46. The system of claim 42, wherein the gateway includes theassociated subscription device.
 47. The system of claim 42, wherein thegateway is distinct from the associated subscription device.
 48. Thesystem of claim 42 wherein the session based protocol is the SessionInitiation Protocol (SIP).
 49. The system of claim 42 wherein thecontroller comprises an application server.
 50. The method of claim 49wherein the application server is operative to generate the subscriptionmessage using a predetermined key press markup language.